Bed motion



June l, 1937. F W SEYBOLD 2,082,184

BED MOTION Filed Oct. 24, 1935 4 Sheets-Sheet 2 June l, y1937. F. w. sEYBoLD 2,082,184

BED MOTION u Fild ocr. 24, 1955 4 sheets-sheet 5 June l, 1937. F. wl sEYBoLD 2,082,184

BED MOTION 4k sheets-sheet 4 V Filed ocu. 24. 1935 llll Il Il Il HI` Patented June 1, 1937 UNITED STTES fr rri by mesne assignments, to American Type Founders Company, Elizabeth, N. J., a corporation of New Jersey Application October 24, 1935, Serial No. 46,608

(Cl. i4-27) 14 Claims.

This invention relates to reciprocating bed motions or the like and more particularly to mechanism of this character especially adapted to be embodied in printing presses of the nat bed and cylinder type.

It is the principal object of this invention to provide a novel and improved reciprocating bed motion by means of which a bed may be oscillated in a complete cycle, the greater portion of the movement of the bed in one direction being at substantially constant speed, while in the other direction the bed has a continually varying veloci y.

This general object and certain of the more specic objects set forth below are substantially the same as those attained by the bed motion disclosed in my copending application Serial No. 41,607, file-d September 21, 1935, the present invention comprising a further application of the same broad principles governing the prior case.

These particular objects include the provision of a bed motion for the purpose set forth in which all of the bed driving gearing remains constantly in mesh, and in which no cams, gates, latches, locks, or any intermittently operating reversing gear is employed; the provision of a bed motion comprising a plurality of differently proportioned trains of mechanisms including cranks, gears, and sliding cross-heads which may be driven from a common source of power and which are adapted to be continuously, positively and operatively connected with said bed through means which are adapted to compound the movements imparted by sai-d trains and to transmit the resultant of these movements to the bed; and the provision o'f a bed motion of this type, the stroke of which is longer than in the case of the standard 3:1 bed motion, thus affording increased form roller coverage for a given cylinder diameter and one which is composed of parts which can be readily produced on standard machine tools at a low cost. i

An object peculiar to the present invention is the provision of a more direct driving connection between the cranks and slides of the transmission of the bed motion and the reciprocating bed, this new arrangement requiring a fewer number of parts through the elimination of certain mechanism employed in the embodiment described in the copending application to which reference has been made, while at the saine time effectively compounding the several motions developed by the crank and gear trains and applying the resultant motion to the bed; this resultant motion having the desired constant speed characteristic throughout the printing period.

Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which one embodiment of the present invention is illustrated by Way of example. The drawings also include certain figures representing graphically the development of the theories underlying the` invention.

In the drawings:

Figures 1-4 inclusive are graphs which illustrate the development of the desired velocity ratio curve just as in the copending application referred to above;

Figures 5 and 6 are diagrams showing the paths or orbits of the crank pins which impart the two separate motions which are compounded and applied to the bed;

Figure 7 is a transverse vertical sectional View of an illustrative model of a printing press of the bed and cylinder type in which the principles of my invention have been embodied; this section being taken as on line 'l-l of Figure 9;

Figure 8 is a partial View in horizontal section taken on line 8-8 of Figure '7 Figure 9 is a vertical longitudinal sectional view taken on line 9 9 of Figure 7 looking in the direction of the arrows;

Figure 10 is a similar view taken on line lli-IB of Figure 7 looking in the opposite direction from that of Figure 9;

Figure l1 is a fragmentary view in horizontal section taken on line lI-ll of Figure 9; and

Figures 12 and 13 are exploded perspective views of the chief elements of the two trains of mechanism which are employed to develop the resolved motions given the bed.

The present device is predicated upon the same theoretical development as that set forth in considerable detail in my copending application and these considerations will be briefly reiterated herein. The prior expedients which have been proposed to drive the bed of a bed and cylinder press at a uniform speed during the printing stroke have been, somewhat complicated and have employed numerous separately functioning driving mechanisms or have resorted to the use of elaborate cam and clutch mechanisms which have been diflicult to keep in proper working condition and have been relatively expensive to produce and maintain. In the present case many unnecessary elements have been eliminated and all of the parts employed can be manufactured on standard machine tools at comparatively low cost.

Probably the most familiar reciprocating motion of the general type employed in machines of this classification is the simple harmonic motion developed as, for example, by the Scotch yoke which comprises a sliding cross-head or yoke driven by a simple crank arm. The general velocity equation of such motion is represented by Vb=wR cos 0, wher-e Vb is the velocity of the yoke, w is the angular velocity of the crank, R is the length 0f the crank, and 6 the angle the crank makes with the horizontal.` The Velocity ratio curve representing the relation of the velocity of the bed to the constant linear velocity of the crank pin is, of course, the sinusoid illustrated in Figure 1 of the drawings and is expressed in this case by the equation y=l00 cos 0. rI'he problem here, as in the case of the invention disclosed in my copending application, is to ilatten one of the loops of this velocity ratio curve so as to produce a constant speed during the period when printing takes place.

This result is attained mechanically in accordance with the following development. The attening of the loop of the simple harmonic velocity ratio curve which represents the printing stroke can be accomplished by the superposition of certain other simple harmonic motion upon the first motions represented by the curve in Figure 1. The velocity ratio equation representing these combined motions, or the displacement equation obtained by integration, can be split into two separate equations which are recognizable as representing hypotrochoids. A hypotrochoid being the path of a point on the radius or radius produced of a circle rolling inside of a Xed circle, these orbits may be obtained by means of a crank fastened to a pinion which meshes with and rolls within a fixed internal gear, the pinion rotating on an arm which is preferably driven at a constant speed. In developing the resultant movement each of the cranks is made to oscillate a sliding cross-head by means of a pin and slot connection, and the motions of these cross-heads, which are the projections of the hypotrochoidal movements of the crank pins on a horizontal line may be added or compounded mechanically and applied to the bed. In the present embodiment the compounding of the motions developed and applied to the sliding cross-heads is obtained by providing upon one of the cross-heads a rotatable gear which meshes with a rack carried by the reciprocating bed and also with another rack carried by the other of said cross-heads. Obviously the effect of the movement of the cross-head which carries the travelling gear will be doubled because it rolls in the rack which is fixed to the other crosshead. 'Ihe latter cross-head is always travelling in the opposite direction from that of the rst cross-head in order that its movement may be added through the travelling gear to the bed.

The proportionate dimensions of the cranks and gears comprising the transmission thus broadly described in order to attain the constant velocity phase of the bed cycle may be obtained from the equations. The development of these constructions and their respective relative dimensions will now be set forth in detail.

In the graphs comprising Figures 1-4 inclusive, the crank angles are the abscissas and the velocity ratios in either direction are the ordinates and are graduated in plus and minus quantities upwardly and downwardly from the zero line, which, opf course, indicates the point of change of direction of movement. In Figure 1, the simple harmonic curve I is represented by the equation y1=100 cos In Figure 2 there is shown a second simple harmonic curve II represented by the equation y2=a cos 2 If these equations I and II be combined or added there is obtained the equation y1,2= cos @+a cos 2 represented by the curve I, II in Figure 3. It will be noted that the velocity ratio curve of this combined harmonic motion shows a sharper loop at the beginning and a somewhat flatter portion between the and 240 points of the cycle.

A third simple harmonic curve III is also shown in Figure 3 and may be expressed by the equation y3=b cos 30. When this third curve is superposed upon the curve I, II the resultant curve is as shown in Figure 4 in which the portion from 120 to 240 is for all practical purposes a straight line. The portion of the cycle containing this at section or constant velocity ratio may be employed on the printing stroke and the continuously variable velocity ratio section represented by the first loop of the curve I, II, III may be employed on the return stroke.

The resulting equation represented by the curve I, II, III in Figure 4 is y1,z,3=100 cos @+11 cos 2@+b cos 3@ (1) in which the values a and b have been selected so that for values of between 120 and 240 the velocity 111,2,3 will remain constant and equal to approximately These values of a and b have been determined as being 46.5 and 10 respectively in order to give an approximately constant velocity between 120 and 240. 'Ihe average value of y1,2,3 is 63.47. Substituting these values for a, and b, the equation for the desired velocity ratio curve shown in Figure 4 becomes y1,2,3=100 cos @+465 cos 2@+l0 cos 3@ (2) y1,2,3=Vb/w Vb=2Vt+Vr= (100 cos @+46.5 cos 2@+10 cos 3@)w L3) where Vb is the velocity of the bed, Vt is the velocity of the cross-head which carries the travelling gear, and Vr is the velocity of the crosshead which carriesthe rack upon which the gear rolls. Then, assuming the Equation (3) can be broken up as follows:

2Vt+Vr= [2(1 cos @+2325 cos 20) (g cos @+10 cos 30) la When the velocities are zero, We have Vt: (f cos @+2325 cos 20) w=0 Vf=(g cos @+10 cos 3@)w=0 Y Then, oi course, the value of n not being zero, the quantities within the parentheses must be equal to zero, thus:

f cos @+2325 cos 20:0 (6) and,

g cos cos 39:0 (7) Furthermore, when the velocities are zero, the

0 angles 0 are either 661 or 29359. Using the 661 value and solving these equations for the values of f and y, we have Substituting these values for f and g in Equation (4), We have The ratio y/f represents the ratio of the length of the crank arms on which the pinions rotate, thus:

g 23.s92 3s.304 '6169 If St is the displacement of the cross-head which carries the travelling gear, then S1: IV: ff cos 0:1- 23.25 cos 20 St=f sin 19d-11.625 sin 20 (8) If Sr is the displacement of the cross-head which carries the rack upon which the gear rolls, then resultant of the combined movement of both cross-heads, expressed by the equation 1 :2(1 sin 0+11.625 sin 26)-l-g sind-??- sm 30 (11) =2(38.304 sin 0+11.625 sin 20) S=clc sin 0-I-c sin (m-1) 0 (13) which is the expression of the ordinate of a hypotrochoid, which as has been already stated, is the path generated by a crank pin fastened to a pinion which meshes with and rolls in a fixed internal gear, the pinion rotating on an arm which for these purposes is driven at a constant speed.

In Equation (13),

S=the displacement of the cross-head of one of the transmissions,

c==the length of the crank on the pinion,

c7c=the length of the crank arm on which the pinion rotates, i. e., the distance between centers of the pinion and internal gear,

pinion crank arm m=the gear ratio between the internalv gear and the pinion,

-the angle of rotation of the pinion driving crank arm.

Equation (11) indicates that the gear ratio m for the travelling gear cross-head must be 3, and for the rack cross-head m must be 4, in order to give sin 219 and sin 30 respectively.

As g represents the length ofthe crank arm whose pinion is one-fourth as large as the internal gear in which it rolls, then the pitch diameter of the internal gear is As f represents the length of the crank arm whose pinion is one-third as large as the internal gear in which it rolls, then the pitch diameter of the internal gear is The development of Equations (14) and (15) is shown graphically in Figures 5.and l6 of the drawings.

The ratio of internal gear pitch diameter The length of the crank which drives the travelling gear cross-head is times the center distance between the. pinion and the internal gear within which it rolls, the ratio of the internal gear to the pinion being 3:1.

In the other transmission train the length of the crank which drives the rack cross-head is times the center distance between this pinion and its associated internal gear, the gear ratio being 4:1. The actual sizes of the internal gears and pinions and of the other elements comprising the transmissions depend, of course, on the size of the sheet to be printed and the desired form roller coverage which determines the length l of the press bed throw. k

With the hypotrochoid equations developed above and the values which have been obtained to t the requirements for producing the bed motion velocity ratio curve illustrated in Figure 4, the actual orbits of the crank pins which describe the hypotrochoid paths may be Ireproduced graphically as in Figures 5 and 6.' The rst transmission with its crank ratio of 142,` as'developed in the preceding paragraphs and its gear ratio of 41:1 will yield a motion whose orbit is represented by the prolate hypotrochoid A1 in Figure 5. The circle B1 representspitch circle of the large internal gear and the circle C1 represents the pinion whose relatively small crank arm is designated c1. The crank pin D1 which drives the sliding cross-head and describes the hypotrochoidal orbit has a horizontal displacement indicated by S1. The angle made by the'crank c1 with the line joining the centers of the circles B1 and C1 at the-ends of the travel of the cross-L head is indicated at 40. p The diagram of the motion developed by the second transmission train is represented in Figure 6 of the drawings in which the path of movement of the crank pin D2 is a prolate hypotrochoid shown at A2. As already developed, the crank ratio of this transmission train is .3034 and its gear ratio is 3:1. The pitch circle of the internal gear is indicated at B2, the rolling pinion at G'z and the crank arm at c2. The horizontal displacement of the crank pin is indicated at S2.

'I'he actual mechanical details of the bed motion which have been referred to in connection with the developments just described will now be set forth in connection with the appropriate constructional figures of the drawings.

For the sake of clearness, there has been illustrated in the drawings a model of a press embodying the principles ofthe invention in which numerous details which are not essential to the illustration of the development of the bed motion are omitted. The press is of the fiat bed, two revolution, constant speed cylinder type and is provided with a base I0 upon which are mounted the side frames I2 which are provided with suitable bearings for the axle I3 of the impression cylinder I4. The reciprocating type bed is illustrated at I5 and is provided in the illustrative model with suitable guides I6 in the side frames I2. A registering gear I1 and rack I8 may be provided on the impression cylinder and bed respectively asjshown in Figure 1'?.V It will be realized, of course, that in a practical embodiment of the invention in an actual press, the bed may also be provided with. the usual roller trucks and other requirements and accessories.

A drive shaft 20 having suitable bearings in the side frames is employed to drive both the bed and the impression cylinder and is itself adapted to be driven by a suitable motor (not shown). Upon the drive shaft are secured the pinions 2| and 22 which are adapted to mesh with and drive the relatively large gears 23 and 24 and serve to initiate the movements of the two transmission trains, which may for convenience be given the general designations P and Q and are illustrated separately in Figures 1 2 and 13 of the drawings. The trains develop the component motions which are applied to the bed.

The gear 24 rotates upon the stub shaft 25 which is carried by one of the side frames I2 and passes through a spacing sleeve 26. The opposite gear 23 is rigidly mounted upon an end of the rotating axle 21 which passes through the bearing and spacing sleeve 28 and carries the gear 30 upon its outer end. 'Ihis gear 30 meshes with the impression cylinder gear 3I which is fixed upon the axle I3, the ratio of the gear 3| to the gear 23 being 1:2, since the impression cylinder makes two revolutions per cycle. On an actual press, of course, suitable means are provided for raising the impression cylinder out of contact with the bed during the non-printing periods.

Intermediate the side frames I2 there are provided longitudinally extending vertically disposed bed supporting frames 34 and 35 which are cut out to receive the stationary internal gears 36 and 31 respectively. The pitch circles of these internal gears 36 and 31 correspond with the circles B1 and B2 on the diagrams in Figures 5 and 6. 'I'he large gear 23 of the gear train P is provided with a shaft 39 upon which a pinion 40 is rotatably mounted. The pinion 40 is adapted to mesh with the internal gear 36 and to roll Within the same, this pinion 40 being indicated diagrammatically at C1 in Figure 5. As developed in the theoretical discussion, the gear ratio of the internal gear 36 and the pinion 4U is 4:1.

In the transmission train Q a similar shaft Aor axle 4I is carried by the gear 24 and provides a bearing for the pinion 42, which rolls in mesh with the internal gear 31, the ratio between the two being 3:1. The pinion 42 is represented in Figure 6 by the circle C2.

A crank disc or plate 44 is rigidly secured to the pinion 40 and lis provided with a crank pin 45. The pinion 42 of the other train carries the crank disc 41 which is provided with a crank pin 48. The cranks 44 and 41 are represented in the diagrams in Figures 5 and 6 by the lines c1 and c2 and the crank pins 45 and 48 are indicated at the points D1`and Dz. By means of the trains of gearing which have just been described, the crank pins 45 and 48 are made to describe the hypotrochoidal orbits indicated at A1 and Az in Figures 5 and. 6.

Longitudinally slidable within grooves formed in the base IU of the press andthe type bed I5 are the slotted cross-heads and 5I. 'I'hese crossheads or slides are shown very clearly in elevation in Figures 9 and 10 of the drawings. The cross-head 50 is provided with a horizontally extending slot 53 which permits the passage of the drive shaft 20 without hindrance during the sliding movements of the cross-head. A vertical slot 55 is also provided in the cross-head 50 within which the squared block 56 is adapted to reciprocate, this block being rotatably carried by the crankpin 45 during its complex movement. It will thus be seen that the cross-head 50 is reciprocated longitudinally through a cycle of movement which is the projection of the hypotrochoidal movement of the crank pin 45 upon a horizontal line parallel with the bed I5. Similarly ther cross-head 5I is provided with a clearance slot 51 for the drive shaft 2D and a vertical slot 58 for receiving the block 6U carried by the crank pin 48 of the transmission system, and it will be understood that the motion of the slide 5I is the projection of the hypotrochoidal movement of the crank pin 48 upon the horizontal.

In the present embodiment, in order to compound these projected hypotrochoidal movements developed by the transmission trains P and Q and impressed upon the slides 50 and 5I, the following mechanism is provided. Upon the underside of the bed I5 there is provided a rack 65, and a rack 66 is secured to the inner face of the slide 5D as by means of the fastening elements 61 or the like. The opposite slide 5I is provided with a stub shaft 69 upon which is rotatably carried the travelling gear 10. This gear 10 meshes at al1 times with both the bed rack and the reciprocating rack 66 andsince, by means of the transmission trains P and Q the slides 50 and 5I are moving in opposite directions, the effects of both movements are compounded by means of the interaction of the travelling gear 10 and the travelling rack 66 and impressed upon the bed I5 through the rack 65.

It will be readily seen from the foregoing description that there is provided by means of the present invention, a reciprocating bed movement which may be driven from' a constantly rotating source such as the drive shaft 20 through the transmission mechanisms comprising the trains P and Q interposed between this source of power and the bed; each of these trains developing a motion which corresponds to the partial Equations (8) and (9) set forth in the earlier portion of the present specification; the two motions being compounded by means of the travelling racks and gears and applied to the bed. The motion imparted to the bed by the travelling gear fullls Cil the constant velocity requirements of the printing stroke of the bed in accordance with the graph in Figure 4 or the drawings. In this construction the length of the bed stroke is considerably longer than that obtained with the conventional 3:1 bed movement, having the same diameter ol impression cylinder. The present invention is, as already pointed out, also distinguished by the feature of continuous gearing engagement and the employment of no auxiliary driving mechanisms, locks, gates, cams or latches.

'Ihe invention may be embodied in bed motions which differ somewhat insofar as the design and arrangement of their functioning parts are concerned, but each such embodiment includes at least two operating parts or portions thereof Which are caused to move along cyclic paths, which paths are dissimilar in character, while maintaining constant phase relationship therebetween, and which comprise portions of the bed driving means. These parts are designated driving elements in claims appended hereto, and where it is stated that the elements move without retracement it is meant that they move continuously in one direction along their respective closed orbits and never retrace their paths during any single cycle of movement.

It will be further understood that various changes and modications. may be made in the embodiment illustrated more or less diagrammatically in the drawings and described herein without departing from the scope of the invention as dened by the following claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A bed movement comprising a bed having a complex harmonic rectilinear motion, approximately one-third of the cycle of which is at uniform velocity, said motion being the resultant of three simple harmonic motions of such characteristics as to produce said uniform velocity portion in said resultant, driving mechanism for said bed comprising two trains of gearing, each of said trains yielding a motion the orbit of which has the form of a prolate hypotrochoid, and means for compounding these motions and for imparting the resultant to the reciprocating bed.

2. A bed movement comprising a bed having a complex harmonic rectilinear motion, approximately one-third of the cycle of which is at uniform velocity, said motion being the resultant of three simple harmonic motions of such characteristics as to producel said uniform velocity portion in said resultant, driving mechanism for said bed comprising two trains of gearing, each of said trains yielding a motio-n the orbit of which has the form of a prolate hypotrochoid, and means for compounding these motions and for imparting the resultant to the reciprocating bed, said last named means comprising slides each driven by one of said trains of gearing and a travelling gear receiving its movement from both of said slides and meshing with a rack carried by said bed.

3. A bed movement comprising a bed having a complex harmonic rectilinear motion, approximately one-third of the cycle of which is at uniform velocity, said motion being the resultant of three simple harmonic motions of such characteristics as to produce said uniform velocity portion in said resultant, driving mechanism for said bed comprising two trains of gearing, each of said trains yielding a motion the orbit of which has the form of a prolate hypotrochoid, and means for compounding these motions and for imparting the resultant to the reciprocating bed, said last named means comprising slides each driven by one of said trains of gearing and a travelling .gear rotatably carried by one of said slides, and meshing with a rack carried by the other of said slides, said gear also meshing with a rack carried by said bed.

4. A reciprocating bed movement comprising a rectilinearly reciprocating bed, a rack on said bed, a travelling gear meshing with said bed rack, a reciprocating drivin-g rack also meshing with said gear, two separate trains of hypotrochoidal gearing, one operatively connected with said travelling gear and the other with said driving rack, both thus adapted to impart motions to said gear, the resultant of which is transmitted to said bed, and comprises a complex harmonic motion approximately one-third of which is at uniform velocity.

5. A reciprocating bed movement comprising.

a rectilinearly reciprocating bed, a pair of trains of mechanism each comprising a crank arm or its equivalent and each rotated at the same angular velocity, a crank pin thereon, a pinion on said crank pin, `a xed internal gear with which said pinion meshes and within which it rolls, another crank rigid with said pinion and having a crank pin thereon, said trains having different gear and crank arm ratios, means for operatively connecting the last named crank pins of each train with said bed for imparting thereto the resultant complex motion of the combined motions of said last named crank pins, the gear ratios of the internal gears and the pinions in the case of one train being 3:1 and the other 4:1, and the respective ratios of the last named cranks to the iirst named crank arms being approximately .303 and .142.

6. A reciprocating bed movement comprising a rectilinearly reciprocating bed, a plurality of trains of mechanism each comprising a crank arm or its equivalent rotated at a constant angular velocity, a crank pin thereon, a pinion on said crank pin, an internal gear with which said pinion meshes and within which it rolls, another crank rigid with said pinion and having a crank pin thereon, a pair of sliding cross-heads driven by said last named cranks, each having a slot therein within which one of said last named crank pin is adapted to slide during its movement, a rack on said bed, .a rack carried by one of said sliding cross-heads, a gear rotatably carried by the other of said cross-heads and disposed in meshing engagement with both of said racks whereby the two component motions generated by said trains are compounded `and the resultant impressed upon said bed.

'7. A reciprocating bed movement comprising a rectilinearly reciprocating bed, a plurality of trains of mechanism each comprising a crank armor its equivalent rotated at a constant angular velocity, a crank pin thereon, a pinion on said crank pin, an internal gear with which said pinion meshes and within which it rolls, another crank rigid with said pinion and having a crank pin thereon, a pair of sliding cross-heads driven by said last named cranks, each having a slot therein within which one of said last named crank pins is adapted to slide during its movement, a rack on said bed, a rack carried by one of said sliding cross-heads, a gear rotatably carried by the other of said cross-heads and disposed in meshing engagement with both of said racks, the gearing trains driving the respective cross-heads being arranged in opposite phase so that the cross-heads move in opposite directions whereby the two component motions generated by said trains are compounded and the resultant impressed upon said bed.

8. A bed movement of the type in which the bed during its working .and return stroke is reciprocated in a plane, comprising the combination with the bed and means for supporting the same for planar movement, of a plurality of movable driving elements, means for moving said elements respectively, without retracement along dissimilar cyclic paths while maintaining constant phase relationship therebetween, both of said paths being prolate hypotrochoids, and means maintaining a constanty operative connection between said elements and the bed, said means receiving motion from both of said elements and transmitting to the bed a motion which is the resultant of the motions of said elements, whereby the bed is caused to move at substantially constant speed during the major portion of its movement in one direction.

9. A bed movement of the type in which the bed during its working and return stroke is reciprocated in a plane, comprising the combination with the bed and means for supporting the same for planar movement, of a plurality of movable driving elements, means for moving said elements respectively, without retracement along dissimilar cyclic paths while maintaining constant phase relationship therebetween, and means maintaining a constant operative connection between said elements and the bed, said means receiving motion from both of said elements and transmitting to the bed a motion which is the resultant of the motions of said elements, whereby the bed is caused to move at substantially constant speed during the major portion of its movement in one direction, said last named means comprising a pair of sliding crossheads each respectively driven by one of said crank pins, a pinion rotatably carried by one of said crossheads, a rack carried by the other of said crossheads and meshing with said pinion, and a rack carried by said bed and also meshing with said pinion.

l0. A bed movement of the type in which the bed during its Working and return stroke is reciprocated in a plane, comprising the combination with the bed an-d means for supporting the same for planar movement, of a plurality of movable driving elements, means for moving said elements respectively, without retracement along dissimilar cyclic paths while maintaining constant phase relationship therebetween, and means maintaining a constant operative connection between said elements and the bed, said means receiving motion from both of said elements and transmitting to the bed a motion which is the resultant of the motions of said elements, whereby the bed is caused to move at substantially constant speed during the major portion o'f its movement in one direction, said last named means comprising a pair of sliding crossheads each respectively driven by one of said crank pins, a pinion rotatably carried by one of said crossheads, a rack carried by the other of said crossheads and meshing with said pinion, and a rack carried by said bed and also meshing with said pinion, said trains of gearing being arranged 180 out of phase whereby said crossheads move in opposite directions.

11. A reciprocating bed movement comprising a rectilinearly reciprocating bed; two trains of mechanism each comprising a crank arm or its equivalent driven at a uniform angular velocity, a pinion rotatably carried on said crank arm, an internal gear concentrically disposed with relation to the center of rotation of said crank arm, said pinion meshing with and adapted to roll within said internal gear, a crank pin rigidly carried by said pinion; each of the crank pins of said trains being dispose-d at a point upon the radius of its pinion at a distance from the center of said pinion which is less than the length of said radius; means for driving said first named crank; means for operatively connecting the crank pins of each train of mechanism with said bed and for imparting to the latter a motion which is the resultant of the combined motions of said trains.

12. A reciprocating bed movement comprising a rectilinearly reciprocating bed; two trains of mechanism each comprising a crank arm or its equivalent driven at a uniform angular velocity, a pinion rotatably carried on said crank arm, an internal gear concentrically disposed with relation to the center of rotation of said crank arm, said pinion meshing with and adapted to roll within said internal gear, a crank pin rigidly carried by said pinion; each of the crank pins of said trains being disposed at a point upon the radius of its pinion at a distance from the center of said pinion which is less than the length of said radius; means for ydriving said rst named crank; means for operatively connecting the crank pins of each train of mechanism with said bed and for imparting to the latter a motion which is the resultant of the combined motions of said trains, said last named means comprising a pair of sliding crossheads each respectively driven byv one of said crank pins, a pinion rotatably carried by one of said crossheads, a rack carried by the other of said crossheads and meshing with said pinion, and a rack carried by said bed and also meshing with said pinion.

13. In a reciprocating bed movement, the combination with a rectilinearly reciprocating bed, a. main driving member for actuating said bed movement and adapted to rotate at a constantr angular velocity, transmission mechanism operatively interposed between said member and said bed and adapted to impart to said bed a rectilinear cyclic motion, at least one-third of the complete cycle of which is uniform, said transmission mechanism comprising two driving elements, means driven by said main driving member to respectively move each of said elements in a separate hypotrochoidal orbit which is symmetrical about its diameter which lies in a plane which is transverse to said bed, two members adapted to reciprocate in directions parallel to that of the movement of said bed, driving connections between said reciprocating members and said driving elements respectively for giving said reciprocating members rectilinear cyclic motions which are represented by the projections of said hypotrochoidal orbits upon their diameters which are parallel to the plane of movement of said bed; and means for combining the motion of said last named members and transmitting the resultant to said bed,- both of said orbits being prolate hypotrochoids.

14. In a reciprocating bed movement, the combination with a rectilinearly reciprocating bed, a main drivingmember for actuating said bed movement and adapted to rotate at a constant angular velocity, transmission mechanism operatively interposed between said member and said bed and adapted to impart to said bed a rectilinear cyclic motion, at least one-third of the complete cycle of which is uniform, said transmission mechanism comprising an epicyclic gear train, a driving element actuated by said gear train and having an orbit which is a hypotrochoid symmetrical about its diameter which lies in a plane transverse to said bed, a second epicyclic gear train, a driving element actuated thereby, the orbit of which is a hypotrochoid of different characteristics but also symmetrical about its diameter which lies in a plane transverse to said bed; a member reciprocated by said rst named element in a straight line path parallel With the direction of movement of said bed in a cycle of movement which is the project-ion of the movement of said iirst named element along its hypotrochoidal orbit upon said straight line, a second member reciprocated in a straight line path parallel to said rst named path and having a cycle of movement which is the projection of the movement of said second named element upon the second straight line path, and means for combining the motions of said members and imparting the resultant to said bed, both of said orbits having the shape of prolate hypotrochoids.

FREDERICK W. SEYBOLD. 

